The purpose of the Macromolecular Core is to provide a key common set of protein and RNA reagents to be used by the other components of the Program Project. The capabilities of the Macromolecular Core include peptide purification and labeling, RNA purification and labeling, isotopic labeling of RNA, and in vitro transcription of RNA. Reagents to provided by the core include: Full RRE RNA; Stem IIB RNA; Stem II RNA; 3'-biotinylation of RNA; Dye-labeling of synthetic RNAs; Isotopic and fluorine labeled RNAs; Rev protein, unlabeled and 15N-labeled; Rev protein mutants and deletions; and Dye-labeling of synthetic peptides. The Macromolecular Core consolidates the in-house expertise necessary to prepare these reagents, and facilitates interactions among the components by making a common set of reagents available to the program.